Initial implementation of .grab for Set/Bag/Mix

src/core/Bag.pm

@@ -23,7 +23,10 @@ my class Bag does Baggy {
         self.delete_key($a);
     }
     method delete_key($a --> Int) is hidden_from_backtrace {
-        X::Immutable.new( method => 'delete', typename => self.^name ).throw;
+        X::Immutable.new( method => 'delete_key', typename => self.^name ).throw;
+    }
+    method grab($count = 1 --> Int) is hidden_from_backtrace {
+        X::Immutable.new( method => 'grab', typename => self.^name ).throw;
     }
 
     method Bag { self }

src/core/Baggy.pm

@@ -76,12 +76,16 @@ my role Baggy does QuantHash {
     method list() { self.keys }
     method pairs() { %!elems.values }
 
-    method pick ($count = 1) {
-        return self.roll if $count ~~ Num && $count == 1;
+    method grab ($count = 1) { self.pick($count, :BIND) }
 
-        my $total = self.total;
-        my $picks = $total min $count;
-        my @pairs = %!elems.values.map( { $_.key => $_.value } );
+    method pick ($count = 1, :$BIND) {
+        return self.roll if $count ~~ Num && $count == 1 && !$BIND;
+
+        my $total  = self.total;
+        my $picks  = $total min $count;
+        my @pairs := $BIND
+          ?? %!elems.values
+          !! %!elems.values.map( { .key => .value } );
 
         map {
             my $rand = $total.rand.Int;

src/core/Mix.pm

@@ -14,7 +14,10 @@ my class Mix does Mixy {
         self.delete_key($a);
     }
     method delete_key($a --> Real) is hidden_from_backtrace {
-        X::Immutable.new( method => 'delete', typename => self.^name ).throw;
+        X::Immutable.new( method => 'delete_key', typename => self.^name ).throw;
+    }
+    method grab($count = 1 --> Real) is hidden_from_backtrace {
+        X::Immutable.new( method => 'grab', typename => self.^name ).throw;
     }
 
     method Mix { self }

src/core/Mixy.pm

@@ -14,6 +14,10 @@ my role Mixy does Baggy  {  # should really be QuantHash, but that's for later
         ~ ')';
     }
 
+    method grab ($count = 1) {
+        fail ".grab is not supported on a {.self.^name}";
+    }
+
     method pick ($count = 1) {
         fail ".pick is not supported on a {.self.^name}";
     }

src/core/Set.pm

@@ -17,7 +17,10 @@ my class Set does Setty {
         self.delete_key($a);
     }
     method delete_key($k --> Bool) is hidden_from_backtrace {
-        X::Immutable.new( method => 'delete', typename => self.^name ).throw;
+        X::Immutable.new( method => 'delete_key', typename => self.^name ).throw;
+    }
+    method grab ($count = 1) {
+        X::Immutable.new( method => 'grab', typename => self.^name ).throw;
     }
 
     method Set { self }

src/core/Setty.pm

@@ -66,6 +66,7 @@ my role Setty does QuantHash {
 
     method list() { %!elems.values }
     method pairs() { %!elems.values.map({ $_ => True }) } 
+    method grab($count = 1) { %!elems{ %!elems.keys.pick($count) }:delete }
     method pick($count = 1) { %!elems.values.pick($count) }
     method roll($count = 1) { %!elems.values.roll($count) }